The invention relates to an enameled tubular built-in unit which can be inserted into and fixed at the nozzle of a container and which is enameled at all places exposed to the product and is usable as a dip pipe.
Enameled built-in units of this kind are known which can be inserted through a nozzle of an enameled reactor comprising an agitator and may have an inner diameter between 25 and 200 mm and a total length between about 850 and 3150 mm and may be used to introduce or to press out liquids or to attack with gas.
For reactors used in the chemical and pharmaceutical industry often means for sampling during operation are used. As tubes for sampling usual dip tubes may be used. Known embodiments of such dip tubes bring about the disadvantage, that specifically for the sampling tube a nozzle at the container is necessary. However, in the case of enameled reactors the number of nozzles is limited. Furthermore, in the case of enameled reactors containing an agitator the number and size of the nozzles is standardized in the most cases. The number of nozzles often cannot be increased out of design reasons. Therefore it is desirable that the sampling tube could be combined with another unit. In this connection it is already known to design a temperature detection unit in such a manner, that it can be inserted in and removed from an enameled built-in unit, which may be an agitation baffle (DE 38 18 957 A1).
If one tries to combine an enameled dip tube with another enameled built-in unit, the difficulty arises, that the demands and the design criteria, resp., of such built-in units are very different. Agitation baffles normally must have larger cross sections in order to cause the necessary agitation effect and to withstand static and dynamic loads. On the other hand, the cross sections of the suction and flow-off conduits of a sampling system should be as small as possible, in order to keep the displacement amounts of the pump small and in order to avoid settling in the conduits, e.g. in the case of suspensions.